Humans have evolved to take more care of themselves. Salt and sugar being the basic ingredient of every Indian cuisine, people are curious to find a healthy substitute for them. But as it is ' the healthy substitute ' for sugar, there is still a long road to travel to find the one for salt.
At present, available in the market are low sodium salts. The main motive of any salt substitute is to reduce the sodium content of salt. It has been long since the human tongue has been adjusted to the insatiable taste of salt(NaCl). Table salt is a compound formed by mainly sodium and chloride ions. Sodium Chloride is an inorganic metal halide. Major dishes and food products use NaCl as a defining factor of flavor. Not only it acts as a flavor enhancer ,but also is used as a preservative for food products like pickle,dried fish,canned meat and meat products etc. But focusing on the brighter side we always fail to understand the vitality of its overuse. Salt is a major ingredient of Indian diet. It is true that our bodily needs of sodium are fulfilled to the major portion by sodium chloride.
Sodium is one of the major mineral electrolytes required by the body for maintenance of external as well as internal fluids of the cells in the body. It helps in maintaining nerve impulse, contraction of muscles and regulation of body pH.
Chloride has functions similar to sodium's as an electrolyte, while it helps in maintaining acid-base balance in the body. Blood chloride levels change in accordance with level of sodium since chloride acts as a buffer
RDA recommends 2g Na/day for an adult which contributes to 5g NaCl per day. But an average Indian consumes about 11g per day. From bread and butter in breakfast to spicy veggies and daal, we consume a hefty amount of Na. Na balance in the body is maintained by the kidney. The kidney filters sodium by glomeruli and is reabsorbed from 5-10% according to body needs. But elevated levels of sodium in the body accounts to increase in blood pressure. Extra sodium in the bloodstream pulls water into blood vessels increasing total blood volume in the blood vessels and hence increases blood pressure. Elevated levels of Na in the body also increases the threat of cardiovascular disease, renal insufficiency and edema. High sodium intake stimulates thirst and appetite and subsequently increases energy intake that leads to obesity.
To limit Na intake, Artificial salts were introduced with a purpose to present low Na salt in our dining tables. They are estimated to deal with the risks of hypertension and cardiovascular disease. Artificial salts have Na substituted by K(potassium). Since, K daily RDA recommendation is more than sodium i.e. 3510mg per day,it is expected to limit Na intake even if salt is taken more.
But,high K intake is fatal to health. It leads to hyperkalemia causing tiredness, nausea and trouble breathing. Moreover, Artificial salts are detested in food due to its bitter and metallic after taste.
Tata salt, India's largest selling salt. I did a case study and the result is alarming from the consumer's way of consumption . According to the ingredient information panel on the packet of 'Tata salt' and 'Tata lite', Tata salt contains 38.7g Na per 100 g of salt whereas Tata lite contains 33.2g of Na per 100g of salt and 7.8g K per 100g of salt. This concluded that only 20% of sodium was replaced by potassium in Tata lite(a low sodium salt or a salt substitute). This explains that blindly accepting low sodium salts to appease our younger with salty taste does not rule out the fact that we are still consuming a good amount of Na.
Other salt substitutes being acknowledged are seaweed and MSG (monosodium glutamate).
Seaweed naturally tastes salty and is rich in minerals. But it is not necessary that all seaweeds are a healthier option over NaCl, some red and brown seaweeds have high amounts of Na and K. It totally depends on the type of seaweed used. For example, 2g of mara seaweed contains 0.08g or less Na;according to a study. Seaweed is also not a very economic option.
MSG has no or some amount of Na present. FAO defines it as a generally recognized safe substance. Keeping in mind all the controversies MSG has gone through of not being safe for human consumption, little amount to substitute NaCl is acceptable;says WHO.
New studies reveal, developing compounds that can act similar to NaCl on Na receptor taste cells. Accordingly any taste perception is an illusion created by the electric nerve impulse that the brain detects when taste molecules interact with the receptor site. Salt perception via receptor cells is a bit more complicated than other tastant molecules. Salt tasting follows two different procedures assigned to different groups of cells. The Amiloride sensitive and The Amiloride insensitive pathway.
Now; the question arises: what is amiloride?
Amiloride is a chemical compound ;which is a pyrazine ring with carbonylguanidinum substituent. In high pH ( salt pH- 8.7), guanidinum group is deprotonated and the compound turns neutral. This lowers activity on sodium channels.
Hence, amiloride sensitive pathway is sensitive to even small amounts of Na ions because the functioning of amiloride affects the functioning of sodium channels. Whereas, amiloride insensitive channels are not affected by amiloride mechanism and hence require large amounts of salt to get detected.
So, sodium or potassium ions, when interacting with taste cells specifically epithelial sodium channels ,the ions usually disturb the charge on the membrane and depolarization in the channel occurs. This increases the electric potential. The difference in electric potential results in a signal generated to the brain to recognize salty taste. As for the potassium ions, some trace ions at the end of perception get detected by bitter taste gustatory cells resulting in bitter aftertaste in artificial salts. Scientists are working on developing a compound that functions similarly to Na ion channel mechanism, and can be a healthy salt substitute.
Artificial salts still have a lot to be discovered about. True health care lies in awareness about the food we eat. We can start by replacing our high sodium diet with the naturally flavoured diet enhanced by oregano, pepper,herbs etc. Opt for a low sodium snacks i.e. 140mg salt or below per 100g of product. Consumption of limited salts be it normal or low-sodium salt.